The present invention relates to a device for driving twist pendulums.
Conventionally, a twist pendulum has been used for a table clock or the like. Generally, the pendulum is attached to a lower portion of a pendulum shaft projecting downward from a mechanism casing, and is driven to rotate by magnetic action between a magnet and a driving coil housed in the casing, while the rotational angle of the pendulum is restricted by spring force of a hair spring, so that the pendulum continues the rotation repeatedly.
Recently, it has been said that the market for twist pendulum clocks is changing from the mass consumption one to the individualized and sensitized one. In order to cope with such a change, it is necessary to make the added value of the commodity high, and a great demand for a commodity cannot be expected unless individuality or unexpectedness is provided to the commodity. In this point of view, the conventional twist pendulum can not satisfy the variety of requirements of various demands in the market because there is provided only one pendulum on a pendulum shaft, such that the pendulum is very simple in movement, monotonous as a whole, has few decorative parts, and thus lacks interest as a commodity.
An object of the present invention is to provide a device for driving twist pendulums in which the twist pendulum is made to have a more decorative functional appeal and to have a change in movement so as to raise the value of the commodity.
According to the present invention, in a device for driving twist pendulums, there is provided a pendulum shaft operating as a driving shaft and a pipe-like pendulum shaft arranged concentrically with the first-mentioned shaft. Twist pendulums are attached to the respective pendulum shafts, a driving wheel and a transmission gear are provided on the first-mentioned pendulum shaft, a drive transmission gear is provided on the second pendulum shaft, and the driving wheel is arranged to be driven to rotate by magnetic force between a magnet and a driving coil and the rotational angle of the driving wheel is restricted by spring force of a hair spring. There is also provided an intermediate gear for transmitting the rotating force of the transmission gear on the first pendulum shaft to the drive transmission gear, and the drive transmission gear and the transmission gear are made to reverse their respective directions of rotation.
Being driven by the driving wheel, the first of the pendulum shafts is rotated so as to rotate one of the twist pendulums in a first predetermined direction, and then the rotation of that twist pendulum is reversed by the spring force of the hair spring, the reversible rotation being repeated in the same manner in a predetermined rotational angle. The other pendulum shaft is also rotated by the rotating force of the driving wheel, but the force to do so is transmitted from a transmission gear on the first pendulum shaft to a drive transmission gear on the second pendulum shaft through an intermediate gear wheel, so that the second twist pendulum is rotated and then reversed. Thus, the second twist pendulum is rotated in a predetermined angle in the direction opposite to the first twist pendulum and then it also is reversed.